In my last column, we examined the procedure of properly converting spot colors into accurate process color equivalents within Adobe Illustrator.
This month we will continue our exploration of spot color conversions, this time using Adobe InDesign.
It is possible to get the same, accurate results when converting spot colors to process equivalents no matter whether you are using Photoshop, Illustrator, or as we will soon see, InDesign. It is important to have the correct settings and use the correct procedures.
Naturally, these procedures are different for each application. Hey, if it were easy we wouldn't need graphic arts in the first place, would we?
To demonstrate this proper procedure in InDesign, I'll begin by putting together a set of spot color samples in Illustrator (see Figure 1). I've taken one of the spot colors, Pantone 354 C, and converted it within Illustrator using the procedure detailed in my last column and the standard SNAP ICC Profile. As you can see from the dialog box, this color converts to a CMYK equivalent of approximately 80/1/100/0, which is the same value produced by Photoshop. I then saved the Illustrator file in the Illustrator EPS format.
Ready to convert
Figure 2 shows the default Swatches panel in InDesign. After importing the Illustrator EPS file you will see that the spot colors contained within the Illustrator file have been automatically added to the Swatches panel (Figure 3). Next, I added another instance of the Pantone 354 C swatch directly within InDesign (Figure 4). I'm now ready to convert my spot colors to their process equivalents.
I'll begin by selecting the Ink Manager option from the Swatches panel drop-down menu (Figure 5). From the Ink Manager panel (Figure 6), I need to ensure that both the "all Spots to Process" and the "Use Standard Lab Values for Spots" option checkboxes located at the bottom of the panel are checked. This will ensure that the spot color L*a*b* values - the numbers that indicate what the color should actually look like - are used when converting the spot colors. Failure to check the Lab option box means that InDesign will simply use the default CMYK values no matter which ICC Profile you are using for your conversions.
Today, where graphics are involved, most workflows are set up to process two basic file types: EPS and PDF. If I want to generate an EPS file I will need to make sure that the appropriate destination ICC Profile is selected in the Color Settings Panel. As shown in Figure 7, I have selected the standard SNAP Profile.
From the File>Export menu I can select from amongst several file type options, including EPS and PDF. If I select the EPS option I will be presented with the dialog box shown in Figure 8. For accurate spot color conversion you can select to generate either a PostScript Type 2 or Type 3 file using the CMYK color model. If, instead, I select to export a PDF file, I will see the dialog box shown in Figure 9. For correct spot color conversion I will need to select the option to have InDesign "Convert to
Destination" and select the appropriate Destination ICC Profile, in this example the SNAP Profile.
When following the above steps I will generate either an EPS or a PDF file where the spot colors have been accurately converting using L*a*b* reference values and my desired ICC Profile and where all three of the Pantone 354 C swatches have identical CMYK values. The results will match the conversions demonstrated in prior columns when Photoshop or Illustrator were used. Give it a try and prove it to yourself.
Next time we will look at how one final graphic application handles spot colors.
John Nate is technical sales manager for EFI. He can be reached at 262.691.1290 or firstname.lastname@example.org.